com.bstek.dorado.util.StringAliasUtils.java Source code

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Here is the source code for com.bstek.dorado.util.StringAliasUtils.java

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/*
 * This file is part of Dorado 7.x (http://dorado7.bsdn.org).
 * 
 * Copyright (c) 2002-2012 BSTEK Corp. All rights reserved.
 * 
 * This file is dual-licensed under the AGPLv3 (http://www.gnu.org/licenses/agpl-3.0.html) 
 * and BSDN commercial (http://www.bsdn.org/licenses) licenses.
 * 
 * If you are unsure which license is appropriate for your use, please contact the sales department
 * at http://www.bstek.com/contact.
 */

package com.bstek.dorado.util;

import java.security.NoSuchAlgorithmException;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.lang.RandomStringUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.bstek.dorado.core.Configure;

/**
 * ???
 * 
 * @author Benny Bao (mailto:benny.bao@bstek.com)
 * @since Jan 19, 2009
 */
public abstract class StringAliasUtils {
    private static final Log logger = LogFactory.getLog(StringAliasUtils.class);

    private static final int TOTAL_CHAR_NUM = 62;

    private static final char HEX_DIGITALS[] = { // ??? 16 
            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };

    private static Map<String, String> aliasMap = new HashMap<String, String>();
    private static Map<String, String> stringMap = new HashMap<String, String>();

    private static int toOrd(char c) {
        if (c >= 'A' && c <= 'Z')
            return c - 'A';
        else if (c >= 'a' && c <= 'z')
            return c - 'a' + 26;
        else if (c >= '0' && c <= '9')
            return c - '0' + 52;
        else
            throw new IllegalArgumentException("Unsupported char [" + c + "].");
    }

    private static char toChar(int i) {
        if (i >= 0 && i < 26)
            return (char) (i + 'A');
        else if (i >= 26 && i < 52)
            return (char) (i + 'a' - 26);
        else if (i >= 52 && i < 62)
            return (char) (i + '0' - 52);
        else
            throw new IllegalArgumentException("Unsupported char code [" + i + "].");
    }

    private static String toHexString(char c) {
        if (c > 127) {
            throw new IllegalArgumentException("Unsupported char [" + c + "].");
        }

        String s = Integer.toHexString(c);
        if (s.length() == 1)
            return '0' + s;
        else
            return s;
    }

    /**
     * ???
     */
    public static String getUniqueAlias(String s) {
        if (StringUtils.isEmpty(s)) {
            return "";
        }

        if (Configure.getBoolean("view.useStringAlias", false)) {
            String alias = stringMap.get(s);
            if (alias == null) {
                if (Configure.getBoolean("view.useRandomStringAlias", true)) {
                    do {
                        alias = RandomStringUtils.randomAlphanumeric(10);
                    } while (aliasMap.containsKey(alias));
                } else {
                    alias = generateOrganizedAlias(s);
                }
                aliasMap.put(alias, s);
                stringMap.put(s, alias);
            }
            return alias;
        } else {
            return s;
        }
    }

    private static String generateOrganizedAlias(String s) {
        String alias;
        int len = s.length();
        int[] bv = new int[len * 2];
        for (int i = 0; i < len; i++) {
            String hex = toHexString(s.charAt(i));
            bv[i * 2] = toOrd(hex.charAt(0));
            bv[i * 2 + 1] = toOrd(hex.charAt(1));
        }

        int code1 = 0, code2 = 0, code3 = 0, code4 = 1, code5 = 1, code6 = 1, code7 = 1, code8 = 1;
        for (int i = 0; i < bv.length; i++) {
            int n = bv[i];

            code1 += n;
            code1 %= TOTAL_CHAR_NUM;

            code2 += (i * n);
            code2 %= TOTAL_CHAR_NUM;

            code3 += ((bv.length - i) * n) + i;
            code3 %= TOTAL_CHAR_NUM;

            code4 *= n;
            code4 %= TOTAL_CHAR_NUM;
            if (code4 == 0)
                code4 = 1;

            code5 *= (i * (n + 1));
            code5 %= TOTAL_CHAR_NUM;
            if (code5 == 0)
                code5 = 1;

            code6 *= ((bv.length - i) * n) + i;
            code6 %= TOTAL_CHAR_NUM;
            if (code6 == 0)
                code6 = 1;

            code7 *= (i * (n + 7));
            code7 %= TOTAL_CHAR_NUM;
            if (code7 == 0)
                code7 = 1;

            code8 *= ((bv.length - i) * (n + 3));
            code8 %= TOTAL_CHAR_NUM;
            if (code8 == 0)
                code8 = 1;
        }
        StringBuffer sb = new StringBuffer(8);
        sb.append(toChar(code1)).append(toChar(code2)).append(toChar(code3)).append(toChar(code4))
                .append(toChar(code5)).append(toChar(code6)).append(toChar(code7)).append(toChar(code8));
        alias = sb.toString();

        while (aliasMap.containsKey(alias)) {
            logger.warn("The string alias [" + alias + "] -> [" + s + "] is already exists.");
            alias += toChar((int) (Math.random() * TOTAL_CHAR_NUM));
        }
        return alias;
    }

    /**
     * ???
     */
    public static String getOriginalString(String alias) {
        if (Configure.getBoolean("view.useStringAlias", false)) {
            return aliasMap.get(alias);
        } else {
            return alias;
        }
    }

    public static String getMD5(byte[] source) throws NoSuchAlgorithmException {
        java.security.MessageDigest md = java.security.MessageDigest.getInstance("MD5");
        md.update(source);
        byte tmp[] = md.digest(); // MD5  128 ? 16 
        char str[] = new char[16 * 2]; // ? 16 ?? 16
        // ? 32 
        int k = 0; // ??
        for (int i = 0; i < 16; i++) { //  MD5 ??? 16
            // ?
            byte byte0 = tmp[i]; // ? i 
            str[k++] = HEX_DIGITALS[byte0 >>> 4 & 0xf]; // ? 4 ??
            str[k++] = HEX_DIGITALS[byte0 & 0xf]; // ? 4 ??
        }
        return new String(str); // ???
    }

    public static String getMD5(String source) throws NoSuchAlgorithmException {
        return getMD5(source.getBytes());
    }
}